1 // weak_undef_file2.cc -- test handling of weak undefined symbols for gold 2 3 // Copyright (C) 2008-2016 Free Software Foundation, Inc. 4 // Written by Cary Coutant <ccoutant (at) google.com>. 5 6 // This file is part of gold. 7 8 // This program is free software; you can redistribute it and/or modify 9 // it under the terms of the GNU General Public License as published by 10 // the Free Software Foundation; either version 3 of the License, or 11 // (at your option) any later version. 12 13 // This program is distributed in the hope that it will be useful, 14 // but WITHOUT ANY WARRANTY; without even the implied warranty of 15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 // GNU General Public License for more details. 17 18 // You should have received a copy of the GNU General Public License 19 // along with this program; if not, write to the Free Software 20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 21 // MA 02110-1301, USA. 22 23 // We test that we correctly deal with weak undefined symbols. 24 // We need to make sure that the symbol is resolved to zero 25 // by the linker and that no dynamic relocation is generated. 26 27 // This source is used to build a shared library that defines 28 // the weak undefined symbol referenced by the main program. 29 // The main program will be linked with a library that does not 30 // provide this definition, so that the symbol remains undefined. 31 // Through the use of the embedded RPATH, the program will load 32 // this alternate shared library that does define the symbol, 33 // so that we can detect whether the symbol was left for runtime 34 // resolution. 35 36 37 #include <cstdio> 38 39 #include "weak_undef.h" 40 41 int is_such_symbol_ = 1; 42 int no_such_symbol_ = 2; 43 44 extern int v2 __attribute__ ((weak)); 45 46 int *v3 = &v2; 47 48 int 49 t1() 50 { 51 return no_such_symbol_; 52 } 53 54 // Test that a weak reference from a shared library to a symbol 55 // defined in the main program does get resolved. 56 57 int 58 t2() 59 { 60 return (&v2 == NULL) ? -1 : v2; 61 } 62 63 // Test that a weak reference from a shared library to a symbol 64 // defined in the main program does get resolved. 65 66 int 67 t3() 68 { 69 return (v3 == NULL) ? -1 : *v3; 70 } 71
